A pad-mounted transformer includes an enclosure or tank having a wall to which various components of the transformer are mounted, such as a low voltage bushing, a high voltage bushing, a ground strap, a stand-off bracket, etc. The enclosure includes a door which is movable between an open position providing access to the various components of the transformer, and a closed position preventing access thereto.
In the past, a transformer door is maintained in its closed position by means of a combination bolt and padlock locking arrangement. The sill of the enclosure includes a padlock hasp which extends through a slot formed in a locking bracket mounted to the door, such that the hasp extends through the slot when the door is closed. In this manner, a padlock is secured to the hasp to prevent the door from being moved to its open position. In combination with the padlock and hasp, the prior art contemplates a bolt adapted to extend through an opening formed in the locking bracket and adapted for engagement with a nut mounted to the sill adjacent the padlock hasp. The bolt has an unconventional head, such as a pentagonal head, to prevent the bolt from being disengaged from the nut by unauthorized persons.
In operation, once the door is closed, the user engages the bolt with the nut and fully tightens the bolt. Thereafter, the padlock is engaged with the hasp, and the hasp is preferably located such that the shank of the padlock is located in alignment with the bolt head to prevent access to the bolt head.